The giant magnetostrictive actuator (GMA) with giant magnetostrictive material (GMM) as the core component has wide applications in the field of precision drive and control. In this paper, through the analysis of the GMA coil, the loss and temperature rise characteristics of the GMA have been studied. Then, COMSOL Multiphysics software has been used to model the heat source distribution of the GMM actuator, and the factors affecting the working temperature of the GMM rod have been analyzed. Finally, based on the use requirements of the GMA, magnetic field, and internal temperature distribution characteristics, the heat dissipation scheme of the coil is proposed, and the experimental platform of the GMA with a thermal compensation function is built to verify the temperature characteristics and thermal compensation effect. Studying the internal temperature distribution law of the GMA not only has a guiding significance for the temperature control of the actuator and the design of the cooling system but also reduces the influence of the coil thermal effect on the performance of the transducer and lays the foundation for making full use of the GMM’s potential in high-power transducers.

Aiming at the problem of the lack of a cooperation mechanism of combined relief valves, this paper proposes a new pressure-regulating and pressure-limiting combined relief valve. Combined with the ordinary relief valve dynamic characteristic analysis method, the dynamic model of the combined relief valve under normal working conditions was established, and its dynamic characteristics were simulated using Simulink. The results showed that the multi-pressure stabilization design of the combined relief valve improves its usability and stability. Under the same structural parameters, the overshoot of the combined relief valve was 5.7, and the response time was 12ms, which is better than the ordinary relief valve. Besides, it effectively improves the instability problems, such as the vibration and the large pressure fluctuation of the ordinary relief valve under high pressure and large flow conditions. When the sum of the effective force area on the upper side of the flange of the pressure-regulating valve core and the area of the tail vertebra is equal to the effective force area of the lower side of the flange of the pressure-regulating valve core, the dynamic performance of the relief valve is optimal. For example, if the effective force area under the flange is 1.8cm², then the inlet pressure overshoot is 2.8, and the response time is 10ms. An appropriate volume of the sensitive cavity, the quality of the valve core, and the fluid resistance of the pressure relief valve are factors that can effectively improve the dynamic performance of the pressure-regulating and pressure-limiting combined relief valve.

To enhance the output thrust of a macro–micro precision actuator while maintaining its precision positioning capability, an optimization design method for the macro-motion structure based on Halbach permanent magnet arrays is proposed. By establishing an equivalent magnetic network model of the macro-motion magnetic circuit, the analytical efficiency for the magnetic field distribution is improved. A single-factor analysis method is employed to reveal the influence of key parameters, including axial permanent magnet length, air-gap thickness, and winding thickness, on the maximum output thrust. The Grey Wolf Optimizer is applied to perform comprehensive optimization of the main parameters, yielding a structural dimension combination that maximizes thrust. On the basis of the optimization results, a prototype is fabricated and experimentally tested, and the results show that under a 6A drive current, the macro-motion stage achieves an output thrust of 190.2N, with a relative error of 2.4% compared with the optimized model prediction. Meanwhile, a stroke positioning of 35.32mm is achieved within 25ms, with a maximum nonlinear error of 0.469mm, demonstrating good linearity of displacement output. This method ensures high-thrust output while maintaining rapid precision positioning, providing an effective technical solution for high-load precision drive applications.

To improve the positioning accuracy of macro-micro precision positioning drives, this paper proposes a novel micro-displacement amplification mechanism utilizing a power-function-based flexible hinge. Using the flexible hinge as the basic component, a symmetrical two-stage lever transmission mechanism was designed based on the principle of differential lever amplification. Compared to traditional flexible hinges, power-law flexible hinges can achieve greater deformation displacement under the same input force, while exhibiting lower maximum stress values. Compared to traditional lever-based amplification mechanisms, this mechanism offers higher amplification efficiency and a higher natural frequency. This paper derives the magnification ratio of the mechanism and analyzes the effects of structural parameters on the output displacement and natural frequency. The maximum stress and displacement characteristics of the mechanism were verified through finite element simulation, and experimental validation was subsequently conducted using a magnetostrictive actuator. The results show that the designed amplification mechanism achieves a magnification of 3.953, with a maximum stroke of 186.8 μ m for the microactuator. This mechanism effectively compensates for the positioning errors of the macro-motion platform, achieving a synergistic optimization of long stroke and high precision, and provides a valuable reference for ultra-precision applications.